1. Field of the Invention
This application claims priority from Korean Patent Application No: 2005-7607 filed Jan. 27, 2005 incorporated by reference in its entirety.
The present invention relates to a heat exchanger, and more particularly, to a heat exchanger for carbon dioxide, in which a tank having a number of domes is coupled with a header and a connection member having a connection flow channel is interposed between the header and the tank, thereby easily changing a refrigerant flow channel, reducing the volume of a header tank, and improving productivity, pressure resistance and durability.
2. Background Art
In general, a heat exchanger is installed on a flow channel of a cooling system or a heating system for cooling or heating a predetermined space by exchanging heat in such a way that heat exchange medium flowing inside the passageway sucks the outside heat or radiates its heat to the outside.
Such heat exchanger is classified into a condenser and an evaporator using refrigerant as heat exchange medium and a radiator and a heater core using cooling water as heat exchange medium according to its use purpose.
Referring to FIGS. 1 and 2, a conventional heat exchanger will be described in brief. As shown in the drawings, the heat exchanger 1 includes: a pair of header tanks 10 mounted at right and left sides thereof and spaced apart from each other at a predetermined interval; a number of tubes 20 each of which both end portions are connected to the header tanks 10 for communicating the two header tanks 10 with each other; heat radiation fins 30 interposed between the tubes 20 for promoting heat exchange by widening a heat transmission area; and side supports 40 mounted at the outermost portions of the tubes 20 and the heat radiation fins 30 for protecting them.
Here, each of the header tanks 10 includes a header 11 having a number of tube holes 13 for connecting both ends of the tubes 20, and a tank 12 coupled with the header 11 for forming a passage for flowing refrigerant therein.
Furthermore, baffles 60 are reciprocally mounted inside the header tanks 10 such that refrigerant flows through the tubes 20 in a zigzag form.
In the conventional heat exchanger 1, refrigerant flows into the header tank 10 through an inlet pipe 50. Refrigerant actively exchanges heat with the outside air while flowing through the tubes 20 in the zigzag form, and after that, is discharged through an outlet pipe 51.
Recently, a heat exchanger using carbon dioxide as refrigerant has been developed to solve the problem of global warming. Such carbon dioxide refrigerant is excellent in compression efficiency and in thermal transmission efficiency.
The heat exchanger for carbon dioxide has a structure similar with that of the conventional heat exchanger 1, but can endure high pressure due to an operational characteristic of carbon dioxide refrigerant.
For examples of the heat exchangers for carbon dioxide, Japanese Patent Publication No. 2003-314987 discloses a structure for flowing refrigerant through a hole formed on a side of a tube disposed between the external member and the internal member and through a communication passageway of a tank. Moreover, Japanese Patent Publication No. 2003-172592 discloses a structure for improving durability by forming a hole of the internal member smaller than the width of a tube to reduce the volume of a header, and Japanese patent Publication No. 2003-130584 discloses a structure for surrounding the outer surface of the heat exchanger with a brazing material.
However, such prior art heat exchangers are complicated in structure and deteriorated in productivity, or increase the volume of the header tank since it has the structure for surrounding the outer surface with the brazing material.